Heat sinks for active device substrates such as chip carrier packages are necessary to dissipate heat generated from in-service functioning of the integrated circuitry, which heat could otherwise ruin the active element or chip. Two types of heat sinks with their particular securing means are disclosed in U.S. Pat. Nos. 4,345,276 and 4,587,595. Some heat sinks are known which are adapted to be assembled to a thermally conductive leadless chip-carrying ceramic substrate by a snap-on stamped and formed precisely shaped steel cover which also must hold the substrate within a chip carrier socket by substantial spring force such as about fifteen pounds for a 68-pin contact carrier. One such heat sink and cover assembly for leadless ceramic substrates and housings is sold by AMP Incorporated under Part No. 55358-3. Such a low-profile heat sink is machined aluminum and has three spaced transverse disk-like cooling fins about a short central shaft so that air flow may be forced between the fins which present substantial surface area to the air flow to dissipate heat, which is transmitted to the fins from the central shaft held in firm physical engagement with the substrate. The heat sink is secured to the steel cover holding the substrate in the housing, by opposing plate-like projections from the bottom of the central shaft being trapped under opposing spaced substrate-engaging straps of the cover between rounded bosses thereof when the heat sink is appropriately placed between the straps against the substrate at an angular 45.degree. offset and then rotated. In such a heat sink, the cooling fins are made by parallel blade cuts of a first process step using conventional screw machine apparatus, while the projections must be made by a separate different process step involving prior removal from the screw machine apparatus. It would be desirable to provide an integral heat sink securable to a substrate by retention structures formed by a screw machine apparatus in the same process step as that wherein the cooling fins are formed by parallel blade cuts.
Where a connector needing a heat sink does not require a strong precisely shaped spring clip to secure the chip carrier to the connector, it would be desirable to provide a spring clip of reduced manufacturing expense, requiring reduced spring strength and less intricate shaping.